Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain BAE Systems (Operations) Limited Model BAe 146-200A series airplanes. This proposal would require replacement of the signal summing units (SSUs) for the stall identification system with new, improved parts. This action is necessary to prevent stall identification and stall warning signals from occurring at the same time, leading the flight crew to take action based on erroneous information, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.